The described invention relates in general to control valves for use in industrial and commercial processes, and more specifically to a rotary control valve that includes two rotating valve members each having a volute portion formed therein that further includes a plurality of flow channels that create a variable orifice between the valve members as the valve members rotate.
Process plants typically include numerous control loops networked together to produce a product. Each control loop is designed to maintain an important process variable, e.g. pressure, flow, level, temperature, etc. within a required operating range. Each of these loops receives and may create internal load disturbances that can detrimentally affect process variables. To reduce the impact of such load disturbances, sensors and transmitters may be used to collect information about the process variable and its relationship to a desired set point. The collected information is processed by a system controller, which then directs a control element to correct or compensate for the detected disturbance. A common control element utilized for this purpose is the control valve. Control valves typically manipulate a flowing material, such as gas, steam, water, or chemical composition to compensate for a detected load disturbance and keep the process variable close to or at the desired set point.
Numerous control valves are known and used in many different industrial and commercial processes. While generally effective for their intended purpose, many of these valves are not suited for applications requiring variable regulation or control based on certain system conditions and requirements. Thus, there is a need for a control valve that may be used in situations that require variable flow to regulate one or more processes.